Blast mitigation system for military vehicles

ABSTRACT

Disclosed is a system and method to both reduce a degree of explosive shock waves and to absorb a degree of explosive blast energy from the undercarriage of a vehicle which comprises the use of one or more layers of rigid closed-cell spray polyurethane foam, applied to the armored undercarriage of the vehicle. This invention combines two key aspects: 1) blast suppression or mitigation materials that absorb energy and 2) traditional military hardened armor solutions. The effectiveness of spray applied rigid foam has been proven to both dramatically reduce shock waves and absorb energy from explosive blasts (e.g., IEDs).

CROSS-REFERENCE TO RELATED APPLICATION

This application claims domestic priority to commonly owned, copending U.S. Provisional Patent Application Ser. No. 61/498,236, filed Jun. 17, 2011, the disclosure of which is hereby incorporated herein by reference.

FIELD OF THE INVENTION

This invention is directed to systems, methods and products used to retrofit vehicles, particularly military vehicles, such that the vehicles so modified will dissipate shock and absorb blast energy on the undercarriage of the military vehicles. The intent of this Honeywell blast suppression or mitigation system is to increase crew survivability with a particular focus on the lower human extremities.

BACKGROUND OF THE INVENTION

Improvised Explosive Devices (IEDs) have caused more casualties in Iraq and Afghanistan than any other threat. Soft-skinned vehicles are completely vulnerable and even armored vehicles are not effective protection from larger and newer forms of IEDs.

Mine Resistant Ambush Protected (MRAP) vehicles emerged by 2007 and although they do provide more protection; they are vulnerable to the blast impulse transferred through the undercarriage of the vehicle, which can result in significant occupant injury, even death.

The Honeywell system provides a degree of blast suppression or mitigation to the vulnerable undercarriage of military vehicles. This helps to protect occupant lower body extremities as well as the vehicle and payload.

From its introduction to the US military and space program in the early 1960s, rigid closed-cell polyurethane foam has been utilized in a wide variety of applications. These include ship blast suppression, floatation devices, roof and wall insulation, external fuel tanks for the Space Shuttle, and in the military EITS (Exterior Insulated Temporary Structures) program in Iraq in 2008 and 2009. In all applications, spray applied polyurethane foam insulation has been a vital component of energy conservation.

A number of studies have been conducted on the degree of blast mitigation afforded by rigid foam materials, acting as an energy absorbing layer. Available scientific data provides some empirical rules equating the blast energy absorbed to the density and thickness of the rigid foam vs. the weight of the charge. Those rules permit estimation of the effect of the blast wave on the structural substrate (e.g., wall) behind the energy absorbing layer.

There are four groups of reported applicable data. Three data sets relate the size of the cavity produced in the rigid foam to the rigid foam density and charge mass. The first of these report work by Cooper & Kurowski; the other two, work by Woodfin of Sandia National Laboratories, Sandia Report SAND 2000-0958 (April 2000), the disclosure of which is hereby incorporated herein by reference.

Besides the Sandia National Lab and Lockheed Martin testing, Cooper and Kurowski explored the blast absorbing capabilities of rigid foam of various densities during the 1970s. They considered the cavities produced by charges detonated in the interior of rigid foam blocks. By varying the rigid foam densities and charge weights of explosive (Tetryl), they developed an empirical scaling law for energy absorption by density and explosive charge weights. The work was extended in 1995 and 1996, repeating some imbedded explosions and adding free surface ones as well.

The following references are also relevant to this invention; and these references are hereby incorporated herein by reference:

-   1. Woodfin, R. L, Rigid Polyurethane Foam (RPF) Technology for     Countermines (Sea) Program, Phase I, Sandia Report, SAND 96-2841,     January, 1997 -   2. Woodfin, R. L., D. L. Faucett, B. G. Hance, A. E. Latham, & C. O,     Schmidt, Rigid Polyurethane Foam (RPF) Technology for Countermines     (Sea) Program, Phase II, Sandia Report, SAND 98-2278, October 1999. -   3. Cooper, P. W., & S. R. Kurowski, Scaling Blast Cavity Diameters     in Rigid Foam, Sandia Laboratories memo of Oct. 6, 1975. -   4. Giacofci, T. A, & Costanzo, A. A., An Investigation of Underwater     Explosion shock Mitigation Effectiveness of Rigid Syntactic Foam     Materials, LATA Report CTOOI06(01), Los Alamos Technical Associates,     Inc., Fairfax, Va., for the Defense Advanced Research Projects     Agency, Advanced Submarine Technology Program., April 1990. -   5. Johnson, D. R. & Fischer, S. H., TNT Equivalence of Energetic     Materials, Sandia National Laboratories Explosive Components     Facility OP-905-0009, Issue B, Appendix A, p 7. -   6. Hyde, D. W., CONWEPS Computer code, implementing the equations in     US Army.

The military has used rigid foam products for various blast mitigation applications for well over forty years. These include a wide variety military applications such as ship hull protection (MIL SPEC P24249-A), helmet foam (MIL SPEC R-5001), and protective packing (MIL PRF 26514, MIL-PRF-26514 Type 1, Class 2, Grades A, B or C).

The following abbreviations may be used herein:

EITS (External Insulating of Temporary Structures) IED (Improvised Explosive Devices) HHRA (Health Hazard Risk Assessment) MIL (Military) MRAP (Mine Resistant Ambush Protected) OEM (Original Equipment Manufacturer) PCF (Pounds Per Square Foot) RPF (Rigid Polyurethane Foam) R&R (Repair and Return) SPEC (Specification) TTM (Trailing Twelve Months) SUMMARY OF THE INVENTION

Honeywell's TerraStrong® Blast Mitigation technology provides critical blast suppression or mitigation for military vehicles, covering the entire passenger compartment (i.e., tops, sides, etc.), as well as the rest of the undercarriage, except for the engine. Combined with existing armor systems, this provides improved vehicular protection. Foams of this type may be applied by spray techniques or they may be applied by other techniques, such as by pouring onto or into a desired location or substrate.

In a preferred embodiment, rigid closed-cell spray polyurethane foam (ccSPF) can be used as a valuable tool in protecting vehicles against blasts associated with IED attacks. Honeywell's Blast Mitigation technology potentially reduces bodily injury to the head, limbs and vital organs of the vehicle occupants. It also reduces damage to equipment and the critical functions of the vehicle's operating and weapons systems. Moreover, the energy absorbing layer reduces road noise (rough terrain, gravel roads, etc.) that can impact war-fighter communications within the vehicle. Installed thickness can be varied depending upon the desired effect of the technology application. Examples of useful thickness, which may be applied as one or more individual layers, are up to one inch; up to two inches; up to three inches; up to four inches; up to five inches; up to six inches, and the like. A typical total thickness for most applications is about three inches, typically applied as one or more layers. Foams of this type are known; see for example, U.S. Pat. Nos. 6,545,063 and 7,288,211, and the references cited therein.

Honeywell TerraStrong® Blast Mitigation technology provides a degree of critical blast suppression or mitigation for military vehicles, covering the undercarriage of the entire passenger compartment. Applicable for both new OEM production vehicles and existing vehicle retrofits are possible. The system can be combined with existing MRAP armor systems or applied to non-MRAP conventional military vehicles (see Illustration Assembly C).

The blast suppression or mitigation technology of this invention can be utilized as a stand-alone solution or combined with other blast and energy absorbing protection devices (i.e. mats, seats, mouth guards, harness systems, etc.) to provide additional vehicular and personnel protection. For optimal performance, the application varies depending upon use. On some vehicle designs the system would be introduced above the rolling chassis, and on others, such as MRAPs with bolt-on armor, it would be placed between the vehicle undercarriage and the vehicle armor plating protection (see Illustration Assembly B).

On MRAPs, the foam would be located between the v-hull armor plate and the vehicle passenger compartment undercarriage (see Illustration Assembly A).

Honeywell's TerraStrong® Blast Mitigation technology combines two key aspects: 1) blast suppression or mitigation materials that absorb energy and 2) traditional hardened armor solutions. The effectiveness of the system has been proven to reduce shock waves and absorb energy from explosive blasts.

Accordingly, one embodiment of the invention is a system to protect the vehicle from the shock of the blast wave, i.e., to dissipate the explosive blast wave at the undercarriage of a vehicle, wherein the system comprises one or more layers of rigid closed-cell spray polyurethane foam applied to the undercarriage of the vehicle. A preferred material used herein is Honeywell's TerraStrong® Rigid Foam.

Another embodiment of the invention is a system to absorb explosive blast energy at the undercarriage of a vehicle comprising one or more layers of rigid closed-cell spray polyurethane foam applied to the undercarriage of the vehicle. A preferred material used herein is Honeywell's TerraStrong® Rigid Foam.

Yet another embodiment of the invention is a system to both reflect explosive blast waves and to absorb explosive blast energy from the undercarriage of a vehicle comprising one or more layers of rigid closed-cell spray polyurethane foam applied to the undercarriage of the vehicle. A preferred material used herein is Honeywell's TerraStrong® Rigid Foam.

In each of the foregoing embodiments, a preferred vehicle for implementation of the invention is a military vehicle. In certain military vehicles, the undercarriage of the vehicle comprises a factory installed V-hull design. In certain military vehicles, the undercarriage of the vehicle comprises a bolt-on, e.g., field installed, V-hull design. In certain military vehicles, the undercarriage of the vehicle comprises a flat bottom design. The level of blast resistance of these undercarriage designs can be improved by the present invention.

It should be appreciated by those persons having ordinary skill in the art(s) to which the present invention relates that any of the features described herein in respect of any particular aspect and/or embodiment of the present invention can be combined with one or more of any of the other features of any other aspects and/or embodiments of the present invention described herein, with modifications as appropriate to ensure compatibility of the combinations. Such combinations are considered to be part of the present invention contemplated by this disclosure.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B show a military vehicle before treatment by this invention.

FIG. 2 illustrates Assembly “A” herein, an MRAP with a factory V-hull design modified with the blast suppression or mitigation materials of the present invention.

FIG. 3 illustrates Assembly “B” an MRAP with a bolt-on V-hull design modified with the blast suppression or mitigation materials of the present invention.

FIG. 4 illustrates Assembly “C” a vehicle with a conventional flat bottom design modified with the blast suppression or mitigation materials of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

As described above, one embodiment of the invention is a method of providing a degree of explosive blast shock protection to the occupants of a vehicle comprising adding one or more layers of rigid closed-cell spray polyurethane foam to the undercarriage of the vehicle. A preferred material used herein is Honeywell's TerraStrong® Rigid Foam.

FIGS. 1A and 1B show a military vehicle (a truck) before treatment by this invention. FIG. 1A shows the underside or undercarriage of the vehicle. FIG. 1B is a plan view of the vehicle, shown on a lift which allows the treatment with one or more layers of rigid closed-cell spray polyurethane foam to the undercarriage of the vehicle.

FIG. 2 illustrates Assembly “A” herein, an MRAP with a factory V-hull design modified with the blast suppression or mitigation materials of the present invention. As illustrated therein, the MRAP factory V-hull design has a “V”-shaped armor plate steel form added to the undercarriage of a vehicle. This figure further shows the added layer or layers of blast suppression or mitigation foam, namely one or more layers of rigid closed-cell spray polyurethane, such as Honeywell's TerraStrong® Rigid Foam. The final outside layer is a protective coating over the blast suppression or mitigation foam, namely a silicone coating, or similar protective material.

As described above, another embodiment of the invention is a method of providing explosive blast energy protection to the occupants of a vehicle comprising adding one or more layers of rigid closed-cell spray polyurethane foam to the undercarriage of the vehicle. A preferred material used herein is Honeywell's TerraStrong® Rigid Foam.

FIG. 3 illustrates Assembly “B” an MRAP with a bolt-on V-hull design modified with the blast suppression or mitigation materials of the present invention. As illustrated therein, the MRAP bolt-on V-hull design has a “V”-shaped armor plate steel form that may be added to the existing plate steel undercarriage of a vehicle. This figure further shows a layer or layers of blast suppression or mitigation foam is added to the space between the V-hull and the vehicle undercarriage, namely one or more layers of rigid closed-cell spray polyurethane, such as Honeywell's TerraStrong® Rigid Foam.

As described above, another embodiment of the invention is a method of providing both explosive shock wave protection and explosive blast energy protection to the occupants of a vehicle comprising adding one or more layers of rigid closed-cell spray polyurethane foam to the undercarriage of the vehicle. A preferred material used herein is Honeywell's TerraStrong® Rigid Foam.

FIG. 4 illustrates Assembly “C” a vehicle with a conventional flat bottom design modified with the blast suppression or mitigation materials of the present invention. As illustrated, the vehicle includes a plate steel undercarriage. This figure further shows the added layer or layers of blast suppression or mitigation foam, namely one or more layers of rigid closed-cell spray polyurethane, such as Honeywell's TerraStrong® Rigid Foam added directly to the undercarriage of the vehicle. The final outside layer is a protective coating over the blast suppression or mitigation foam, namely a silicone coating, or similar material.

Honeywell TerraStrong Rigid Foam technology is a two-component polyurethane mixture that is combined at the spray gun to form expanding foam that is applied on MRAPs between the v-hull armor plate and other non-MRAP vehicle passenger compartment undercarriage surfaces. This material has been used in other military projects. See for example, U.S. Patent Publication No. 2011-0303254 and U.S. patent application Ser. No. 13/280,080, filed Oct. 24, 2011. The disclosures of these applications are hereby incorporated herein by reference.

This invention combines two key aspects: 1) blast suppression or mitigation materials that absorb energy and 2) traditional military hardened armor solutions. The effectiveness of spray applied rigid foam has been proven to dramatically reduce shock waves and absorb energy from blasts.

This invention exploits one of the key properties of the polyurethane spray foams, namely the ability to be applied as a sprayable liquid and to conform to the shape of the substrate. As for blowing agents, all liquid blowing agents can be used—HFC-245fa, HFC-365mfc, HFC-365mfc/HFC-227ea mixtures, HCFC-141b, HCFO-1233zd(E) or 1233zd(Z), HFO-1336mzzm(Z), water and less preferred—cyclopentane, isopentane, normal pentane, methyl formate, methylal, trans-1,2-dichloroethylene and gaseous blowing agents like HFC-134a, HFO-1234ze(E), and CO₂. Any and all mixtures of these agents will also be suitable.

In certain embodiments, the closed cell foam may be prepared from a polymer foam formulation containing as a blowing agent a hydrofluorocarbon selected from the group consisting of 1,1,1,3,3-pentafluoropropane, 1,1,1,2-tetrafluoroethane, 1,1,2,2-tetrafluoroethane, 1,1,1,3,3-pentafluorobutane, 1,1,1,2,3,3,3-heptafluoropropane, and mixtures thereof.

As used herein, an effective amount of additive means an amount, based on the amount of blowing agent, which reduces the vapor pressure of a foam formulation B-side to below the vapor pressure of the corresponding foam prepared in the absence of additive. Generally, an effective amount is from about 0.02 to about 10 weight percent, based on the amount of blowing agent.

As used herein, blowing agent composition refers to HFC-245fa or HFC-134a singly or in combination with other non-ozone depleting blowing agents, such as, for example, other hydrofluorocarbons, e.g., difluoromethane (HFC-32), difluoroethane (HFC-152), trifluoroethane (HFC-143), tetrafluoroethane (HFC-134), pentafluoropropane (HFC-245), pentafluorobutane (HFC-365), hexafluoropropane (HFC-236), and heptafluoropropane (HFC-227); C4-C7 hydrocarbons, including but not limited to butane, isobutane, n-pentane, isopentane, cyclopentane, hexane and isohexane; inert gases, e.g., air, nitrogen, carbon dioxide; and water, in an amount of from about 0.5 to about 2 parts per 100 parts of polyol. Where isomerism is possible for the hydrofluorocarbons mentioned above, the respective isomers may be used either singly or in the form of a mixture.

HFC-245fa is a known material and can be prepared by methods known in the art such as those disclosed in WO 94/14736, WO 94/29251, WO 94/29252 and U.S. Pat. No. 5,574,192. Difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoropropane, pentafluorobutane, hexafluoropropane and heptafluoropropane are available for purchase from Honeywell, Inc., Morristown, N.J., USA.

With respect to the preparation of rigid polyurethane or polyisocyanurate foams using a blowing agent comprising 1,1,1,3,3-pentafluoropropane or 1,1,1,2-tetrafluoro-ethane, any of the methods well known in the art can be employed. See Saunders and Frisch, Volumes I and II Polyurethanes Chemistry and Technology (1962). In general, polyurethane or polyisocyanurate foams are prepared by combining under suitable conditions an isocyanate (or isocyanurate), a polyol or mixture of polyols, a blowing agent or mixture of blowing agents, and other materials such as catalysts, surfactants, and optionally, flame retardants, colorants, or other additives.

It is convenient in many applications to provide the components for polyurethane or polyisocyanurate foams in pre-blended foam formulations. Most typically, the foam formulation is pre-blended into two components. The isocyanate or polyisocyanate composition comprises the first component, commonly referred to as the “A” component or “A-side.” The polyol or polyol mixture, surfactant, catalysts, blowing agents, flame retardant, water and other isocyanate reactive components comprise the second component, commonly referred to as the “B” component or “B-side.” While the surfactant and fluorocarbon blowing agent are usually placed on the polyol side, they may be placed on either side, or partly on one side and partly on the other side. Accordingly, polyurethane or polyisocyanurate foams are readily prepared by bringing together the A and B side components either by hand mix, for small preparations, or preferably machine mix techniques to form blocks, slabs, laminates, pour-in-place panels and other items, spray applied foams, froths, and the like. Optionally, other ingredients such as fire retardants, colorants, auxiliary blowing agents, water and even other polyols can be added as a third stream to the mix head or reaction site. Most conveniently, however, they are all incorporated into one B component.

Any organic polyisocyanate can be employed in polyurethane or polyisocyanurate foam synthesis inclusive of aliphatic and aromatic polyisocyanates. Preferred as a class are the aromatic polyisocyanates. Preferred polyisocyanates for rigid polyurethane or polyisocyanurate foam synthesis are the polymethylene polyphenyl isocyanates, particularly the mixtures containing from about 30 to about 85 percent by weight of methylenebis(phenylisocyanate) with the remainder of the mixture comprising the polymethylene polyphenyl polyisocyanates of functionality higher than 2. Preferred polyisocyanates for flexible polyurethane foam synthesis are toluene diisocyanates including, without limitation, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, and mixtures thereof.

Typical polyols used in the manufacture of rigid polyurethane foams include, but are not limited to, aromatic amino-based polyether polyols such as those based on mixtures of 2,4- and 2,6-toluenediamine condensed with ethylene oxide and/or propylene oxide. These polyols find utility in pour-in-place molded foams. Another example is aromatic alkylamino-based polyether polyols such as those based on ethoxylated and/or propoxylated aminoethylated nonylphenol derivatives. These polyols generally find utility in spray applied polyurethane foams. Another example is sucrose-based polyols such as those based on sucrose derivatives and/or mixtures of sucrose and glycerine derivatives condensed with ethylene oxide and/or propylene oxide. These polyols generally find utility in pour-in-place molded foams.

Catalysts used in the manufacture of polyurethane foams are typically tertiary amines including, but not limited to, N-alkylmorpholines, N-alkylalkanolamines, N,N-dialkylcyclohexylamines, and alkylamines where the alkyl groups are methyl, ethyl, propyl, butyl and the like and isomeric forms thereof, as well as heterocyclic amines. Typical, but not limiting, examples are triethylenediamine, tetramethylethylenediamine, bis(2-dimethylaminoethyl)ether, triethylamine, tripropylamine, tributylamine, triamylamine, pyridine, quinoline, dimethylpiperazine, piperazine, N,N-dimethyl-cyclohexylamine, N-ethylmorpholine, 2-methylpiperazine, N,N-dimethylethanolamine, tetramethylpropanediamine, methyltriethylenediamine, and mixtures thereof.

Optionally, non-amine polyurethane catalysts are used. Typical of such catalysts are organometallic compounds of lead, tin, titanium, antimony, cobalt, aluminum, mercury, zinc, nickel, copper, manganese, zirconium, and mixtures thereof. Exemplary catalysts include, without limitation, lead 2-ethylhexoate, lead benzoate, ferric chloride, antimony trichloride, and antimony glycolate. A preferred organo-tin class includes the stannous salts of carboxylic acids such as stannous octoate, stannous 2-ethylhexoate, stannous laurate, and the like, as well as dialkyl tin salts of carboxylic acids such as dibutyl tin diacetate, dibutyl tin dilaurate, dioctyl tin diacetate, and the like.

In the preparation of polyisocyanurate foams, trimerization catalysts are used for the purpose of converting the blends in conjunction with excess A component to polyisocyanurate-polyurethane foams. The trimerization catalysts employed can be any catalyst known to one skilled in the art including, but not limited to, glycine salts and tertiary amine trimerization catalysts, alkali metal carboxylic acid salts, and mixtures thereof. Preferred species within the classes are potassium acetate, potassium octoate, and N-(2-hydroxy-5-nonylphenol) methyl-N-methylglycinate.

Also included in the mixture are blowing agents or blowing agent blends. Generally speaking, the amount of blowing agent present in the blended mixture is dictated by the desired foam densities of the final polyurethane or polyisocyanurate foams products. The polyurethane foams produced can vary in density, for example, from about 0.5 pound per cubic foot to about 40 pounds per cubic foot, preferably from about 1 to about 20 pounds per cubic foot, and most preferably from about 2 to about 8 pounds per cubic foot. The density obtained is a function of how much of the blowing agent, or blowing agent mixture, is present in the A and/or B components, or that is added at the time the foam is prepared. The proportions in parts by weight of the total blowing agent or blowing agent blend can fall within the range of from 1 to about 60 parts of blowing agent per 100 parts of polyol. Preferably from about 10 to about 35 parts by weight of blowing agent per 100 parts by weight of polyol are used.

Dispersing agents, cell stabilizers, and surfactants may be incorporated into the blowing agent mixture. Surfactants, better known as silicone oils, are added to serve as cell stabilizers. Some representative materials are sold under the names of DC-193, B-8404, and L-5340 which are, generally, polysiloxane polyoxyalkylene block co-polymers such as those disclosed in U.S. Pat. Nos. 2,834,748, 2,917,480, and 2,846,458.

Other optional additives for the blowing agent mixture may include flame retardants such as tris(2-chloroethyl)phosphate, tris(2-chloropropyl)phosphate, tris(2,3-dibromopropyl)phosphate, tris(1,3-dichloropropyl)phosphate, diammonium phosphate, various halogenated aromatic compounds, antimony oxide, aluminum trihydrate, polyvinyl chloride, and the like.

The rigid foam is installed to the undercarriage of the designated military vehicles using traditional techniques, thereby protecting the vehicle passenger compartment and its occupants from blasts affecting the undercarriage of military vehicles. As illustrated in FIGS. 1A and 1B, the vehicle retrofit application process consists of jacking up the vehicle or placing it on a lift. Cleaning, masking and spraying operations are managed to ensure optimum form and fit during the application process. The edges of the resulting Rigid Spray Foam can be tapered and sanded to provide a factory installed appearance.

If the rigid spray foam is exposed to the elements without the protection of a bolt-on-and-off v-hull armor plating, a protective coating covering can be applied over the newly installed foam if desired for exposed foam applications. Note that if a color match is required for the vehicle, either the spray foam or the outer coating, can be color matched to meet vehicle color or camouflage requirements. Specialty items or applications may be custom-applied to virtually any desired thickness. The trimming and reassembling process involves hand-trimming and sanding procedures to produce smooth edges. All rubber plugs, tie downs, lines, exhaust, access panels and hitches are unmasked or reinstalled before completion.

The TerraStrong rigid foam technology absorbs a portion of the blast energy and blast wave to lessen the impact of roadside IED explosions. The more energy absorbed by the rigid foam, the less impact on the personnel, equipment and damage to the vehicle itself. Honeywell's blast suppression or mitigation technology reduces bodily injury to the head, limbs and vital organs of the vehicle occupants. It also reduces damage to equipment and the critical functions of the vehicle's operating and weapons systems. Moreover, it reduces road noise (rough terrain, gravel roads, etc.) that can impact war-fighter communications within the vehicle.

Honeywell's vehicle blast protection technology can be applied to various sizes and shapes of current military vehicles. Because it covers the undercarriage of the entire passenger compartment, it provides protection to all of the occupants. Installation of the blast mitigation technology of the present invention can be at various staging sites based on customer requirements (OEM manufacturing or retrofit) or at OEM sites (vehicle assembly and armor manufacturing facilities). Honeywell has the capability to install in-theater retrofits at current military vehicle up-grade facilities, both CONUS and OCONUS, (i.e., Mina Abdulla in Kuwait, regional vehicle repair and return service depot maintenance facilities, or at unit level FOB vehicle maintenance shops).

This technology solution can be applied to a various current military vehicle platforms, and the additional weight would be less than ½-lb per cubic foot using a 6-7 lb/ft³ density rigid foam formulation. For example, an MRAP vehicle with a vehicle passenger undercarriage surface area of 8′×15′ equaling a blast protection surface area of 120 sq. ft. with a three-inch thickness of blast protection foam would add approx. 1½-lbs addition weight to the entire vehicle weight. This invention fits all size and weight military vehicles and only adds a few pounds (1-5 lbs) to total vehicle curb weight depending on application.

Technical Fully-Adhered Vehicle Application

The Rigid Spray Foam to the undercarriage of the designated military vehicles, thereby reduce the impact of explosive blasts to the vehicle passenger compartment and its occupants. See FIGS. 1A, 1B and 2-4.

The vehicle retrofit application process consists of jacking-up the vehicle or placing it on a lift. Cleaning, masking and spraying operations are managed to ensure optimum form and fit during the application process. The edges of the resulting Rigid Spray Foam can be tapered and sanded to provide a factory installed appearance. If foam is exposed to the elements without the protection of a v-hull armor plating, a 34-mil coat of protective coating can be applied over the newly installed foam if desired.

The spray foam polyurethane insulation material may be applied at any desired thickness level, for example ¼ inch thick, ½ inch thick, 1 inch thick, two inches thick, and more, if desired. For most military vehicle blast applications, a range of from two to six inches is employed. Other applications can have greater or lesser thicknesses, as desired for particular applications. Spraying of the foam polyurethane insulation material is done by conventional equipment and methods. See for example, U.S. Pat. No. 6,347,752, the disclosure of which is hereby incorporated herein by reference.

Note that if a color match is required for the vehicle, either the foam or coating can be color matched to meet vehicle color or camouflage requirements. Specialty items or applications may be custom applied to virtually any desired thickness. The trimming and reassembling process involves hand-trimming and sanding procedures to produce smooth edges. All rubber plugs, tie downs, lines, exhaust, access panels and hitches are unmasked or reinstalled before completion.

As used herein, the singular forms “a”, “an” and “the” include plural unless the context clearly dictates otherwise. Moreover, when an amount, concentration, or other value or parameter is given as either a range, preferred range, or a list of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. Where a range of numerical values is recited herein, unless otherwise stated, the range is intended to include the endpoints thereof, and all integers and fractions within the range. It is not intended that the scope of the invention be limited to the specific values recited when defining a range.

It should be understood that the foregoing description is only illustrative of the present invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variances that fall within the scope of the appended claims. 

1. A system to help dissipate explosive blast wave to the undercarriage of a vehicle comprising one or more layers of rigid closed-cell spray polyurethane foam applied to the undercarriage of the vehicle.
 2. A system to partially absorb explosive blast energy at the undercarriage of a vehicle comprising one or more layers of rigid closed-cell spray polyurethane foam applied to the undercarriage of the vehicle.
 3. A system to both help dissipate explosive shock waves and to partially absorb explosive blast energy from the undercarriage of a vehicle comprising one or more layers of rigid closed-cell spray polyurethane foam applied to the undercarriage of the vehicle.
 4. The system of claims 1-3, wherein the vehicle is a military vehicle.
 5. The system of claim 4, wherein the undercarriage of the vehicle comprises a factory installed V-hull design.
 6. The system of claim 5, wherein the thickness of the foam is at least about one inch, applied as one or more individual layers.
 7. The system of claim 5, wherein the thickness of the foam is at least about two inches, applied as one or more individual layers.
 8. The system of claim 5, wherein the thickness of the foam is at least about three inches, applied as one or more individual layers.
 9. The system of claim 5, wherein the thickness of the foam is at least about four inches, applied as one or more individual layers.
 10. The system of claim 5, wherein the thickness of the foam is at least about five inches, applied as one or more individual layers.
 11. The system of claim 5, wherein the thickness of the foam is at least about six inches, applied as one or more individual layers.
 12. The system of claim 4, wherein the undercarriage of the vehicle comprises a bolt-on V-hull design.
 13. The system of claim 12, wherein the thickness of the foam is at least about one inch, applied as one or more individual layers.
 14. The system of claim 12, wherein the thickness of the foam is at least about two inches, applied as one or more individual layers.
 15. The system of claim 12, wherein the thickness of the foam is at least about three inches, applied as one or more individual layers.
 16. The system of claim 12, wherein the thickness of the foam is at least about four inches, applied as one or more individual layers.
 17. The system of claim 12, wherein the thickness of the foam is at least about five inches, applied as one or more individual layers.
 18. The system of claim 12, wherein the thickness of the foam is at least about six inches, applied as one or more individual layers.
 19. The system of claim 4, wherein the undercarriage of the vehicle comprises a flat bottom design.
 20. The system of claim 19, wherein the thickness of the foam is at least about one inch, applied as one or more individual layers.
 21. The system of claim 19, wherein the thickness of the foam is at least about two inches, applied as one or more individual layers.
 22. The system of claim 19, wherein the thickness of the foam is at least about three inches, applied as one or more individual layers.
 23. The system of claim 19, wherein the thickness of the foam is at least about four inches, applied as one or more individual layers.
 24. The system of claim 19, wherein the thickness of the foam is at least about five inches, applied as one or more individual layers.
 25. The system of claim 19, wherein the thickness of the foam is at least about six inches, applied as one or more individual layers.
 26. A method of providing a degree of explosive blast shock mitigation to the occupants of a vehicle comprising adding one or more layers of rigid closed-cell spray polyurethane foam to the undercarriage of the vehicle.
 27. A method of providing a degree of explosive blast mitigation to the occupants of a vehicle comprising adding one or more layers of rigid closed-cell spray polyurethane foam to the undercarriage of the vehicle.
 28. A method of providing a degree of both explosive shock wave mitigation and explosive blast energy mitigation to the occupants of a vehicle comprising adding one or more layers of rigid closed-cell spray polyurethane foam to the undercarriage of the vehicle.
 29. The method of claims 26-28, wherein the vehicle is a military vehicle.
 30. The method of claim 29, wherein the undercarriage of the vehicle comprises a factory installed V-hull design.
 31. The method of claim 29, wherein the undercarriage of the vehicle comprises a bolt-on V-hull design.
 32. The method of claim 29, wherein the undercarriage of the vehicle comprises a flat bottom design. 